Apparatus for Closing Containers

ABSTRACT

The invention is an apparatus for closing containers, preferably pharmaceutical containers. The apparatus includes a closing device which surrounds a closing element of the container. The closing device is provided with a magnetic mechanism, such as an electromagnetic coil, which generates a magnetic force and thereby deforms the closure element. The deformation of the closure element closes and seals the opening of the container. The closing device is designed such that the closing device applies the magnetic force to only a part of the closure element, for example, the edge of the closure element.

PRIOR ART

The invention is based on an apparatus for closing containers as generically defined by the preamble to the independent claim. DE 44 47 347 C1 has disclosed an apparatus for closing containers, in particular cylindrical ampules, vials, or the like with closure caps. A pivoting frame takes each container from a container cell of a conveyor and supplies it to a crimping roller. The rotating motion is initiated mechanically. In the event of a missing cap or an incorrect positioning of the container, the crimping rollers or the shoulder can damage the container, which can lead to breakage, particularly with glass containers, and therefore to contamination of the crimping machine. This is problematic particularly with pharmaceutical containers for toxic products.

U.S. Pat. No. 3,581,456 has disclosed a magnetic reshaping method for container caps. In this case, a magnetic force is exerted on the entire cap in order to bring it into form-locked engagement with the neck of the container to be closed. Particularly with delicate containers for pharmaceutical applications, this can lead to damage of the container.

ADVANTAGES OF THE INVENTION

The apparatus according to the present invention for closing containers, preferably pharmaceutical containers, has a closing device that generates a magnetic force for reshaping at least one closure element in order to close a container. The closing device according to the present invention is embodied so that the closing device exerts the magnetic force on only a part—preferably the edge—of the closing element. In this way, it is possible to produce a crimping that seals the closing element—and possibly a stopper secured by it in the neck of the container. On the other hand, the magnetic force is not exerted on the entire region of the container covered by the cap, thus making it possible to reduce possible damages to the container. In addition, the magnetic reshaping is particularly suitable for pharmaceutical applications since they have very high requirements for contamination prevention. In addition, the magnetic reshaping makes it possible to further increase production output because it is possible to dispense with complex mechanical reshaping processes that act on the closure element with direct contact. There is an overall reduction in the risk of damage to the containers, thus reducing a transmission of the emerging product into the entire crimping carousel.

According to a suitable modification, the closing device encloses the closure element and in the enclosed state, at least one magnet is situated so that the magnetic force is exerted on only a part of the closure element. In addition, the corresponding structural arrangement of the magnet assures that only the edge to be reshaped is subjected to the corresponding force of the closing device. This makes it possible to exert force even more selectively on the desired regions, thus reducing the probability of damage to the containers.

In a preferred modification, shielding means are provided that shield at least part of the closure element from the magnetic force generated by the closing device. Depending on the geometry of the closure element used, the shielding means can be inserted between the magnet and the closure element in order to prevent the exertion of magnetic force on this part of the closure element. Different shielding means can be used without requiring modification of the closing device for each closure element.

According to a suitable modification, the closing device is used to supply the closure element or to take it away. The closing device is already adapted to the closure element and now can also be used to supply the closure element to the container to be closed and therefore also to perform the transport function of the closure element and of the closed container. This double function makes it possible to do away with a separate supply or removal device.

According to a suitable modification, the closing device is composed of at least two parts that are moved into place laterally in relation to the longitudinal axis of the container to be closed. It is thus possible to refrain from moving the closing device above the opening of the container to be closed, which under some circumstances, can lead to a contamination with particles adhering to the closing device. For this reason, a lateral approach motion achieved by means of this embodiment is preferable.

According to a suitable modification, the generation of a magnetic field that exerts the magnetic force on the part of the closure element to be reshaped is only initiated once the two parts come into contact with each other.

Other advantageous modifications ensue from additional dependent claims and the description.

DRAWINGS

An exemplary embodiment of the apparatus according to the present invention for closing containers is shown in the drawings and will be described in greater detail below.

FIG. 1 shows a cross section though a container to be closed,

FIG. 2 shows a cross section through components of the closure of the container,

FIG. 3 shows a cross section through a closure element with a protective cap,

FIG. 4 shows a closing device with a container to be closed situated in the closing position,

FIG. 5 shows a closing device with a container in the removal position, and

FIG. 6 shows a top view of an alternative exemplary embodiment of a closing device with a container.

A container 10, which is preferably used in the pharmaceutical sector, must be closed. To this end, a stopper 12 is pressed into the neck of the container 10 and a closure element 14 is then placed on top of it. It is preferably an aluminum cap whose edge has a part 16 to be reshaped. Above the closure element 14, there is a protective cap 18 mechanically connected to the stopper 12. The protective cap 18 is circular. The difference between the outer radius of the protective cap 18 and the outer radius of the closure element 14 produces an air gap L. The detailed depiction of the protective cap 18 is omitted in FIG. 4. It is, however, provided there and the outer radius of the protective cap 18 is selected so as to produce an overhang that protects the protective cap 18 somewhat and facilitates removal. The closing device 20 is embodied as a cylindrical part that encloses at least the reshaping part 16 of the closure element 14, spaced apart by the air gap L. A circular opening is provided in the closing device 20 through which a die 24 can be moved, preferably also in relation to the closing device 20. Through the use of this die 24, a force can be exerted on the closure element 14 in the axial direction. The stopper 12 must be pressed into place in a definite fashion (as a rule, the stopper 12 has already been pressed into place but can slip back out again before the closure occurs)—this state should be fixed by means of the closure element 14. In the edge region of the cylindrical closing device 20, at least one electromagnet 22 is provided; three coils are shown here by way of example. The electromagnet 22 is situated so that in the reshaping position of the closing device 20, the electromagnet 22 imparts a magnetic field to the part 16 of the closure element 14 to be reshaped (i.e. its rim). This electromagnet 22 is not provided in the upper region of the closure element 14 so that no force is exerted on the part that is not to be reshaped. After the reshaping is complete, the contour of the closure element 14 fits the neck of the container 10. The die 24 can then move in the axial direction in relation to the closing device 20 in order to remove the container 10 from the vicinity of the closing device 20.

The crimping of a cap as an example for a closure element 14 should occur without mechanical contact with the closing device 20. This makes it possible to solve the contamination of containers 10 by particles and the risk of container damage or transmission of the product with which the container 10 is filled and a poor capacity for being cleaned. According to the present invention, the contactless crimping is executed by means of magnetic field reshaping. In this case, a very powerful electromagnet 22 is situated spaced by a small air gap L apart from the material to be reshaped, in this case the closure element 14. The closure element 14 must be made of a highly conductive material such as aluminum or steel. Aluminum is particularly suitable for this purpose. The electromagnet 22 is briefly supplied with a powerful electrical pulse from a capacitor, thus generating a very powerful magnetic field. The closure element 14 to be reshaped is repelled so powerfully by the magnetic field that, depending on the field intensity and on the constitution and material thickness of the closure element 14, a reshaping of the latter occurs. For the crimping of caps, as an example of a closure element 14, onto pharmaceutical containers 10 with stoppers 12, a rotationally symmetrical head is used as part of a closing device 20, which, in a first exemplary embodiment, is placed onto the closure element 14 from above and with a definite pressure of the die 24, fixes the system composed of the stopper 12 and closure element 14 in position in the container 10. Preferably, the die 24 serving as a pressure plate in the head is nonconductive. It can also be conductive, provided that this does not interfere with the reshaping process. This should be possible particularly in the case of partial reshaping procedures. At the lower edge of the head of the closing device 20, depending on the height of the closure element 14, a narrow electromagnet 22 is provided, which is spaced by an air gap L of for example 1 mm apart from the edge 16 of the closure element 14 that is to be reshaped. This electromagnet 22 then receives a powerful electrical pulse and generates a very powerful magnetic field for a short period of time in the millisecond range, which exerts a repelling action on the closure element 14. This field lays the part 16 of the closure element 14 to be reshaped precisely against the neck of the container 10 so that it is no longer possible for the stopper 12 to slide out. This method requires no rotation of the container 10 or of the closing device 20. It likewise eliminates mechanical friction between the crimping roller and the closure element 14. The magnetic reshaping treats the container 10 significantly more gently than conventional crimping methods. The mechanical movement for the reshaping of up to 600 closure elements per minute can be implemented by means of a plurality of parallel-functioning heads of a closing device 20 and a simple shared movement in a linear fashion—as in the filling procedure.

A centering device 26 is provided that brings the container 10 into a predefined position in relation to the closing device 20. Preferably, the centering device 26 sets an air gap L with the same spacing on all sides between the closing device 20 and the part 16 of the closure element 14 to be reshaped. In an alternative embodiment, the lateral overhang of the protective cap 18 is suitable for defining the desired air gap between the closing device 20 and the part 16 to be reshaped in that the inner radius of the cylindrical casing of the closing device 20 essentially coincides with the outer radius of the protective cap 18. Consequently, the protective cap 18 more or less serves as a stop for the closing device 20.

The container 10 is closed as follows. A stopper 12 that has not yet been pressed into place is situated in the neck of the container 10. Then, an external device or the head of the closing device 20 supplies a closure element 14. In a first alternative, the closing device 20 moves together with the die 24 onto the container 10 from above in the axial direction. The die 24 presses the stopper 12 into the neck of the container 10 via the closure element 14 and remains in this holding position. Then the cylindrical part of the closing device 20 slides over the closure element 14 so that in the reshaping position, the electromagnet 22 is situated adjacent to the part 16 to be reshaped. This forms the air gap L between the closing device 20 and the outer edge of the closure element 14. The electromagnet 22 is acted on with a pulse in the microsecond range, thus producing a magnetic field. This exerts force on the part 16 of the closure element 14 to be reshaped. The part 16 of the closure element 14 to be reshaped adapts to the outer contour of the neck of the container 10. The die 24 then presses against the stopper 12 in the axial direction to eject the container 10 from the closing device 20.

The die 24 can be a component of the closing device 20 by being structurally connected to it. Additionally, it would also be possible for the adjustable force on the stopper 12 to be introduced by means of pressure on the container 10 from underneath pushing it against the die 24. After the reshaping of the container 10 with the reshaped closure element 14 is completed, the container is ejected from the closing device 20 through a linear movement of the die 24 in the direction of the central axis of the container. With an acceleration of the operating cycles, it is possible for a number of closing devices 20, for example reshaping devices, functioning simultaneously or in parallel, to affix closure elements 14 to a number of containers 10 by means of reshaping. In addition, it is also possible for a plurality of reshaping devices, as components of the closing device 20, to be situated in series in the transport direction of the containers 10. Devices of this kind arranged in series can be structurally connected to one another. A multitude of electromagnets 22 of the different closing devices 20 could receive the electrical charge from the same electrical source. The closing device 20 could travel along with the container 10 during the reshaping operation.

In an alternative exemplary embodiment that is not shown, the electromagnet 22 could extend over the entire length of the closure element in the axial direction. In order to assure that a magnetic force is exerted only on the part 16 to be reshaped, it is then possible for shielding means to be inserted into the air gap L in the upper region of the closure element 14. The shielding means serve to shield the magnetic field so that no force is exerted on the shielded region of the closure element 14. The electromagnet 22 could also be situated so that it only acts on the region to be reshaped, without shielding means.

In another alternative exemplary embodiment shown in FIG. 6, the closing device 20 does not surround the neck of the container 10 from above, but is instead moved into place perpendicular to the container axis. To this end, the cylindrical part of the closing device 20 is composed, for example, of two shells 20/1, 20/2, each of which contains at least one electromagnet 22. For the sake of better depiction, a gap 30 is shown in FIG. 6, which is closed for the reshaping process. It is then possible for the generation of a magnetic field to be initiated once an electrical contact of the two shells 20/1, 20/2 occurs, causing the closure element 14 to be reshaped. The two shells 20/1, 20/2 together constitute a conductive block, for example a conductive coil. The shells 20/1, 20/2 or halves each have contacts for this purpose, which in the closed state, are used for the contacting of the two shells 20/1, 20/2. Thus, for example, an electrical contact can be closed, which controls the supply of current to the electromagnet 22. Electrical supply lines 28 can be provided for this purpose.

The apparatus according to the present invention is particularly suited to the closing of pharmaceutical containers since they have particularly high requirements for safety. Its use, however, is not limited to them. 

1-15. (canceled)
 16. An apparatus for closing containers, such as a pharmaceutical container having at least one closure element, comprising: a closing device disposed around the closure element for reshaping the closure element in order to close an opening in the container and seal the container; and magnetic means disposed in the closing device for generating a magnetic force which is applied to the closure element and thereby reshapes the closure element, wherein the closing device is embodied so that the magnetic means exerts the magnetic force on only a part of the closure element.
 17. The apparatus according to claim 16, wherein the magnetic means comprises at least one magnet, and wherein the closing device encloses the closure element in a enclosed state such that the at least one magnet is situated so that only the part of the closure element is subjected to the magnetic force.
 18. The apparatus according to claim 16, wherein the closing device comprises shielding means that shield at least a part of the closure element from the magnetic force generated by the magnetic means.
 19. The apparatus according to claim 16, wherein the closing device includes a die that exerts a force on the closure element at least during the reshaping process.
 20. The apparatus according to claim 16, wherein the closing device used is for transporting the closure element and/or the container.
 21. The apparatus according to claim 16, wherein the closing device is composed of at least two parts, that are movable transversely relative to a longitudinal axis of the container to be closed.
 22. The apparatus according to claim 16, further comprising a protective cap disposed on the closure element, wherein an outer diameter of a protective cap is larger than that of the closure element and thereby defines an air gap (L) disposed between the closure element and the closing device.
 23. The apparatus according to claim 1, further comprising a centering device for the container which sets an air gap (L) with the same spacing on all sides between the closing device and the part of the closure element to be reshaped.
 24. The apparatus according to claim 16, further comprising a die holding the closure element by means of a force exerted on the closure element and/or on a stopper in the opening of the container during the reshaping process.
 25. The apparatus according to claim 19, wherein the die is structurally connected to the closing device.
 26. The apparatus according to claim 24, wherein the die is structurally connected to the closing device.
 27. The apparatus according to claim 24, wherein the force on the stopper is introduced by means of pressure exerted on the container from below, pushing the container against the die.
 28. The apparatus according to claim 16, wherein after the reshaping of the closure element is completed, the container is ejected from the closing device by means of a linear movement of the die in the direction of the central axis of the container.
 29. The apparatus according to claim 16, further comprising a plurality of closing devices disposed in parallel, wherein the closing devices function simultaneously to affix closure elements to a plurality of containers by means of reshaping of the closure elements.
 30. The apparatus according to claim 17, wherein the magnet is embodied in the form of an electromagnet.
 31. The apparatus according to claim 29, wherein the magnetic means of each of the plurality of closing devices is embodied in the form of an electromagnet.
 32. The apparatus according to claim 31, wherein the electromagnets of the closing devices are supplied with current from the same electrical source. 